Both oriented and non-oriented ferroxplana with x=0.00, 0.45 were prepared by conventional ceramic method. The magnetostrictions of thus prepared specimens were measured by use of the three terminal capacitor device at room temperature. The magnitude of measured values was approximately five times greater than that of ZnY ferroxplana. The easy-magnetization plane at room temperature of both CoZ and Co0.55 $Zn_{0.45}$Z was their basal plane. The magentostrictions in the basal plane and the other planes showed saturated values at magnetic field intensity of about 2Koe and 4Koe, respectively. The magnetostriction constants for CoZ were -2.4, -10.5, -5.9 and -45.2 , while those for were +0.1, -1.2, -6.3 and -39.0, , respectively.

Mutual interferences of alkali and alkali-earth metals in atomic absorption were examined. For determination of Na or K interfering elements increase the absorbancy, and for Ca or Mg decrease. Since influences of coexisting elements become nearly constant by addition of large amount of same coexisting element, could be use mixed standard solution for alkali or alkali-earth metal determination in the presence of other alkali and alkali-earth metals. The metals can be readily incorporated into scheme of rapid silicate analysis. Precision and accuracy are good.

This study was carried out finding out the relation between the bond materials and grade for vitrified abrasive. Composed materials were changwon clay, Anyang feldpar, Chungju Talc, Chongsong pottery stone, Kimchun quartz which were used as raw materials for the favorable abrasive bond. 30 mesh fused white alumina abrasive grain and 60 mesh green silicon carbide abrasive grain were used. 1. The composition of the bonding materials were chosen as the base according to the results of the pill test. 2. Weight of dextrine, bond and forming water were obtained according to the following. formule : =-0.05X+ 1.5 where : X=weight % of bond =weight % of dextrine =weight %of water 3. The specimen size was 150 mm diameter by 20mn height cylinder, then the specimen was crossed molding by laboratory press. 4. The specimen was dried at around 100-12 in the automatic controlled electric oven. Firing cycle is following : 20/hr. up to 100 12/hr. from 100 to 128 soaking time : 3hrs at 128

Mullite was synthesized by using kaolin and -alumina, and halloysite and aluminum hydroxide as raw materials at the various temperature in the range of 1200-1750C. The degree of mullitization was measured respectively by a quantitative X-ray diffraction method and a chemical analysis method. The rate and the maximum degree of mullitization were found to increase with temperature . The reaction completed at 1600Cfor less than 30 minutes, and yielded 98% mulllite inpurity in the case of kaolin-Al(OH)3. TiO up to 3% was added to the batches of kaolin-Al(OH). the effect of addition on the mullitization was investigated and found to decrease the sintering temperature for the mullitization. The mechanism of TiO addition on the formation of mullite was also discussed.